84 TRANSVERSELY STRIPED MUSCULAR FIBRES. 



solution of soda to the fibres which have been treated with dilute 

 hydrochloric acid, the nuclei swell in the sarcolemma from which 

 the fibrils have been thus removed, and very rapidly disappear ; 

 the very hyaline sarcolemma continues to exhibit a faintly granu- 

 lated appearance. 



These micro-chemical investigations show that the three mor- 

 phological elements which we distinguish in the primitive bundles 

 of muscle differ chemically from one another, constituting respec- 

 tively the true substance of the fibrils, the substance of the nucleus, 

 and the sarcolemma. 



The chemical properties of the substance of the fibrils (syn- 

 tonin) have been already glanced at in p. 68 Qand will be further 

 considered in the Appendix to this volume]. The micro-chemical 

 investigations already made on the substance which may be 

 extracted from the muscles with dilute hydrochloric acid, lead us 

 to concur in Liebig's view of this being the matrix of true mus- 

 cular fibre. We have already observed that the primitive bundles 

 of muscle, even when they have been digested for a prolonged 

 period in a solution of nitre at a temperature of 30 or 40, do not 

 exhibit any change under the microscope which can justify us in 

 believing that there is the slightest partial solution of the finest 

 muscular fibrils. 



As, however, these experiments were mostly made with the 

 flesh of oxen and calves, and as the fibrin of the blood of oxen is, 

 as is well known, nearly insoluble in a solution of nitre, whilst 

 that of other animals is dissolved very readily after a short diges- 

 tion (see vol. i, p. 351), the precaution was taken to select swine's 

 flesh, which was freed as far as possible of its fat (the blood-fibrin 

 of the pig being very readily soluble in a solution of nitre), and, 

 after cutting it into very fine pieces, to rinse it with distilled water 

 until the fluid that was pressed out of it exhibited no traces of 

 albumen. After this mass had been freed as far as possible from 

 soluble protein-bodies, it was digested for two or three days in a 

 solution of nitre, of the strength already specified ; but there was 

 no trace of any dissolved protein-substance which was either 

 coagulable by heat, or precipitable by acetic acid or any other 

 reagent. The syntonin contained naturally in the muscular fibrils 

 is, therefore, quite as insoluble in a solution of nitre as that which 

 is artificially obtained from the muscles by means of hydrochloric 

 acid, &c. 



We are led to conclude from the micro-chemical reagents already 

 indicated, that the substance of the nuclei inclosed in the sarco- 



